Inital commit

build.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+set -o errexit
+
+pip install -r requirements.txt
+python manage.py collectstatic --no-input
+python manage.py migrate

splitchat/.env.example

@@ -0,0 +1,7 @@
+# Copy to .env and fill in values for local development
+SECRET_KEY=your-secret-key-here-generate-a-random-one
+DEBUG=True
+ALLOWED_HOSTS=localhost,127.0.0.1
+DATABASE_URL=sqlite:///db.sqlite3
+# Leave REDIS_URL blank to use in-memory channel layer (dev only)
+# REDIS_URL=redis://localhost:6379

splitchat/build.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+set -o errexit
+
+pip install -r requirements.txt
+python manage.py collectstatic --no-input
+python manage.py migrate

splitchat/config/asgi.py

@@ -0,0 +1,20 @@
+import os
+import django
+from django.core.asgi import get_asgi_application
+from channels.routing import ProtocolTypeRouter, URLRouter
+from channels.auth import AuthMiddlewareStack
+from channels.security.websocket import AllowedHostsOriginValidator
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'config.settings')
+django.setup()
+
+from core.routing import websocket_urlpatterns
+
+application = ProtocolTypeRouter({
+    'http': get_asgi_application(),
+    'websocket': AllowedHostsOriginValidator(
+        AuthMiddlewareStack(
+            URLRouter(websocket_urlpatterns)
+        )
+    ),
+})

splitchat/config/settings.py

@@ -0,0 +1,122 @@
+import os
+from pathlib import Path
+import environ
+
+BASE_DIR = Path(__file__).resolve().parent.parent
+
+env = environ.Env(
+    DEBUG=(bool, True),
+    ALLOWED_HOSTS=(list, ['*']),
+)
+
+# Read .env if present
+environ.Env.read_env(BASE_DIR / '.env')
+
+SECRET_KEY = env('SECRET_KEY', default='dev-secret-key-change-in-production-please-12345')
+DEBUG = env('DEBUG')
+ALLOWED_HOSTS = env('ALLOWED_HOSTS')
+
+INSTALLED_APPS = [
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.messages',
+    'django.contrib.staticfiles',
+    'channels',
+    'core',
+]
+
+MIDDLEWARE = [
+    'django.middleware.security.SecurityMiddleware',
+    'whitenoise.middleware.WhiteNoiseMiddleware',
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+]
+
+ROOT_URLCONF = 'config.urls'
+
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [BASE_DIR / 'templates'],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'core.context_processors.sidebar_context',
+                'core.context_processors.sidebar_context',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = 'config.wsgi.application'
+ASGI_APPLICATION = 'config.asgi.application'
+
+# Database
+DATABASE_URL = env('DATABASE_URL', default=f'sqlite:///{BASE_DIR}/db.sqlite3')
+if DATABASE_URL.startswith('sqlite'):
+    DATABASES = {
+        'default': {
+            'ENGINE': 'django.db.backends.sqlite3',
+            'NAME': BASE_DIR / 'db.sqlite3',
+        }
+    }
+else:
+    import dj_database_url
+    DATABASES = {'default': dj_database_url.config(default=DATABASE_URL, conn_max_age=600)}
+
+# Channels / Redis
+REDIS_URL = env('REDIS_URL', default=None)
+if REDIS_URL:
+    CHANNEL_LAYERS = {
+        'default': {
+            'BACKEND': 'channels_redis.core.RedisChannelLayer',
+            'CONFIG': {'hosts': [REDIS_URL]},
+        }
+    }
+else:
+    CHANNEL_LAYERS = {
+        'default': {
+            'BACKEND': 'channels.layers.InMemoryChannelLayer',
+        }
+    }
+
+AUTH_PASSWORD_VALIDATORS = [
+    {'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator'},
+    {'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator'},
+    {'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator'},
+    {'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator'},
+]
+
+LANGUAGE_CODE = 'en-us'
+TIME_ZONE = 'UTC'
+USE_I18N = True
+USE_TZ = True
+
+STATIC_URL = '/static/'
+STATIC_ROOT = BASE_DIR / 'staticfiles'
+STATICFILES_DIRS = [BASE_DIR / 'static']
+STATICFILES_STORAGE = 'whitenoise.storage.CompressedManifestStaticFilesStorage'
+
+DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
+LOGIN_URL = '/login/'
+LOGIN_REDIRECT_URL = '/'
+LOGOUT_REDIRECT_URL = '/login/'
+
+# Production security (applied when DEBUG=False)
+if not DEBUG:
+    SECURE_SSL_REDIRECT = True
+    SECURE_HSTS_SECONDS = 31536000
+    SECURE_HSTS_INCLUDE_SUBDOMAINS = True
+    SESSION_COOKIE_SECURE = True
+    CSRF_COOKIE_SECURE = True
+    SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')

splitchat/config/urls.py

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+from django.contrib import admin
+from django.urls import path, include
+
+urlpatterns = [
+    path('admin/', admin.site.urls),
+    path('', include('core.urls')),
+]

splitchat/config/wsgi.py

@@ -0,0 +1,16 @@
+"""
+WSGI config for config project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/6.0/howto/deployment/wsgi/
+"""
+
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'config.settings')
+
+application = get_wsgi_application()

splitchat/core/admin.py

@@ -0,0 +1,31 @@
+from django.contrib import admin
+from .models import ChatRoom, Membership, Message, Event, Expense, ExpenseSplit, UserProfile
+
+@admin.register(ChatRoom)
+class ChatRoomAdmin(admin.ModelAdmin):
+    list_display = ('name', 'invite_code', 'created_by', 'member_count', 'created_at')
+    search_fields = ('name', 'invite_code')
+
+@admin.register(Membership)
+class MembershipAdmin(admin.ModelAdmin):
+    list_display = ('user', 'room', 'is_admin', 'is_active', 'joined_at')
+
+@admin.register(Message)
+class MessageAdmin(admin.ModelAdmin):
+    list_display = ('sender', 'room', 'msg_type', 'content', 'created_at')
+
+@admin.register(Event)
+class EventAdmin(admin.ModelAdmin):
+    list_display = ('title', 'room', 'created_by', 'total_amount', 'is_settled', 'created_at')
+
+@admin.register(Expense)
+class ExpenseAdmin(admin.ModelAdmin):
+    list_display = ('description', 'event', 'amount', 'paid_by', 'split_type')
+
+@admin.register(ExpenseSplit)
+class ExpenseSplitAdmin(admin.ModelAdmin):
+    list_display = ('expense', 'user', 'amount')
+
+@admin.register(UserProfile)
+class UserProfileAdmin(admin.ModelAdmin):
+    list_display = ('user', 'display_name', 'avatar_color')

splitchat/core/apps.py

@@ -0,0 +1,8 @@
+from django.apps import AppConfig
+
+class CoreConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'core'
+
+    def ready(self):
+        import core.signals

splitchat/core/consumers.py

@@ -0,0 +1,112 @@
+import json
+from channels.generic.websocket import AsyncWebsocketConsumer
+from channels.db import database_sync_to_async
+from django.contrib.auth.models import User
+from django.utils import timezone
+
+
+class ChatConsumer(AsyncWebsocketConsumer):
+    async def connect(self):
+        self.room_id = self.scope['url_route']['kwargs']['room_id']
+        self.room_group_name = f'chat_{self.room_id}'
+        user = self.scope['user']
+
+        if not user.is_authenticated:
+            await self.close()
+            return
+
+        # Verify membership
+        is_member = await self.check_membership(user, self.room_id)
+        if not is_member:
+            await self.close()
+            return
+
+        await self.channel_layer.group_add(self.room_group_name, self.channel_name)
+        await self.accept()
+
+        # Broadcast join event
+        await self.channel_layer.group_send(
+            self.room_group_name,
+            {'type': 'user_join', 'username': user.username,
+             'display_name': await self.get_display_name(user)}
+        )
+
+    async def disconnect(self, close_code):
+        user = self.scope.get('user')
+        if user and user.is_authenticated:
+            await self.channel_layer.group_send(
+                self.room_group_name,
+                {'type': 'user_leave', 'username': user.username,
+                 'display_name': await self.get_display_name(user)}
+            )
+        await self.channel_layer.group_discard(self.room_group_name, self.channel_name)
+
+    async def receive(self, text_data):
+        data = json.loads(text_data)
+        msg_type = data.get('type', 'chat_message')
+        user = self.scope['user']
+
+        if msg_type == 'chat_message':
+            content = data.get('content', '').strip()
+            if not content:
+                return
+            message = await self.save_message(user, content)
+            await self.channel_layer.group_send(
+                self.room_group_name,
+                {
+                    'type': 'chat_message',
+                    'message_id': str(message.id),
+                    'content': content,
+                    'sender': user.username,
+                    'display_name': await self.get_display_name(user),
+                    'avatar_color': await self.get_avatar_color(user),
+                    'initials': await self.get_initials(user),
+                    'timestamp': message.created_at.strftime('%H:%M'),
+                    'full_timestamp': message.created_at.isoformat(),
+                }
+            )
+
+    async def chat_message(self, event):
+        await self.send(text_data=json.dumps({'type': 'chat_message', **event}))
+
+    async def user_join(self, event):
+        await self.send(text_data=json.dumps({'type': 'user_join', **event}))
+
+    async def user_leave(self, event):
+        await self.send(text_data=json.dumps({'type': 'user_leave', **event}))
+
+    async def room_update(self, event):
+        """Broadcast when events/expenses are created"""
+        await self.send(text_data=json.dumps({'type': 'room_update', **event}))
+
+    @database_sync_to_async
+    def check_membership(self, user, room_id):
+        from core.models import Membership
+        return Membership.objects.filter(user=user, room_id=room_id, is_active=True).exists()
+
+    @database_sync_to_async
+    def save_message(self, user, content):
+        from core.models import Message, ChatRoom
+        room = ChatRoom.objects.get(id=self.room_id)
+        return Message.objects.create(room=room, sender=user, content=content)
+
+    @database_sync_to_async
+    def get_display_name(self, user):
+        try:
+            return user.profile.name
+        except Exception:
+            return user.username
+
+    @database_sync_to_async
+    def get_avatar_color(self, user):
+        try:
+            return user.profile.avatar_color
+        except Exception:
+            return '#6366f1'
+
+    @database_sync_to_async
+    def get_initials(self, user):
+        try:
+            return user.profile.get_avatar_initials()
+        except Exception:
+            return user.username[:2].upper()

splitchat/core/context_processors.py

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+from .models import ChatRoom, Membership
+
+def sidebar_context(request):
+    if request.user.is_authenticated:
+        rooms = ChatRoom.objects.filter(
+            memberships__user=request.user,
+            memberships__is_active=True
+        ).order_by('name')
+        return {'rooms': rooms}
+    return {'rooms': []}

splitchat/core/forms.py

@@ -0,0 +1,64 @@
+from django import forms
+from django.contrib.auth.forms import UserCreationForm
+from django.contrib.auth.models import User
+from decimal import Decimal
+from .models import ChatRoom, Event, Expense, ExpenseSplit, Membership, UserProfile
+
+
+class SignUpForm(UserCreationForm):
+    email = forms.EmailField(required=True)
+    first_name = forms.CharField(max_length=50, required=False)
+    last_name = forms.CharField(max_length=50, required=False)
+
+    class Meta:
+        model = User
+        fields = ('username', 'first_name', 'last_name', 'email', 'password1', 'password2')
+
+
+class ChatRoomForm(forms.ModelForm):
+    class Meta:
+        model = ChatRoom
+        fields = ('name', 'description')
+        widgets = {
+            'name': forms.TextInput(attrs={'placeholder': 'Room name...', 'autocomplete': 'off'}),
+            'description': forms.Textarea(attrs={'placeholder': 'What is this room for?', 'rows': 3}),
+        }
+
+
+class EventForm(forms.ModelForm):
+    event_date = forms.DateTimeField(
+        required=False,
+        widget=forms.DateTimeInput(attrs={'type': 'datetime-local'}),
+        input_formats=['%Y-%m-%dT%H:%M'],
+    )
+
+    class Meta:
+        model = Event
+        fields = ('title', 'description', 'location', 'event_date')
+        widgets = {
+            'title': forms.TextInput(attrs={'placeholder': 'Event title...'}),
+            'description': forms.Textarea(attrs={'rows': 3, 'placeholder': 'Details...'}),
+            'location': forms.TextInput(attrs={'placeholder': 'Location (optional)'}),
+        }
+
+
+class ExpenseForm(forms.Form):
+    description = forms.CharField(max_length=200, widget=forms.TextInput(attrs={'placeholder': 'What was this for?'}))
+    amount = forms.DecimalField(max_digits=10, decimal_places=2, min_value=Decimal('0.01'),
+                                 widget=forms.NumberInput(attrs={'placeholder': '0.00', 'step': '0.01'}))
+    paid_by = forms.ModelChoiceField(queryset=User.objects.none(), empty_label="Who paid?")
+    split_type = forms.ChoiceField(choices=Expense.SPLIT_CHOICES, initial='equal',
+                                    widget=forms.RadioSelect)
+    participants = forms.ModelMultipleChoiceField(
+        queryset=User.objects.none(),
+        widget=forms.CheckboxSelectMultiple,
+        required=True,
+    )
+
+    def __init__(self, *args, room=None, **kwargs):
+        super().__init__(*args, **kwargs)
+        if room:
+            members = User.objects.filter(memberships__room=room, memberships__is_active=True)
+            self.fields['paid_by'].queryset = members
+            self.fields['participants'].queryset = members
+            self.fields['participants'].initial = members

splitchat/core/management/commands/create_demo.py

@@ -0,0 +1,55 @@
+from django.core.management.base import BaseCommand
+from django.contrib.auth.models import User
+from core.models import ChatRoom, Membership, Event, Expense, ExpenseSplit, UserProfile
+from decimal import Decimal
+
+class Command(BaseCommand):
+    help = 'Create demo data for testing'
+
+    def handle(self, *args, **kwargs):
+        # Users
+        alice, _ = User.objects.get_or_create(username='alice', defaults={'email': 'alice@example.com', 'first_name': 'Alice'})
+        alice.set_password('demo1234')
+        alice.save()
+        UserProfile.objects.update_or_create(user=alice, defaults={'avatar_color': '#6366f1'})
+
+        bob, _ = User.objects.get_or_create(username='bob', defaults={'email': 'bob@example.com', 'first_name': 'Bob'})
+        bob.set_password('demo1234')
+        bob.save()
+        UserProfile.objects.update_or_create(user=bob, defaults={'avatar_color': '#ec4899'})
+
+        carol, _ = User.objects.get_or_create(username='carol', defaults={'email': 'carol@example.com', 'first_name': 'Carol'})
+        carol.set_password('demo1234')
+        carol.save()
+        UserProfile.objects.update_or_create(user=carol, defaults={'avatar_color': '#22c55e'})
+
+        # Room
+        room, _ = ChatRoom.objects.get_or_create(name='Weekend Trip 🏕️', defaults={
+            'description': 'Planning our camping trip!',
+            'created_by': alice,
+        })
+        for user, admin in [(alice, True), (bob, False), (carol, False)]:
+            Membership.objects.get_or_create(user=user, room=room, defaults={'is_admin': admin})
+
+        # Event
+        event, _ = Event.objects.get_or_create(title='Camping Supplies Run', defaults={
+            'room': room, 'created_by': alice,
+            'description': 'Buying supplies for the trip',
+            'location': 'REI Downtown',
+        })
+
+        if not event.expenses.exists():
+            e1 = Expense.objects.create(event=event, description='Tent & Sleeping bags',
+                amount=Decimal('120.00'), paid_by=alice, split_type='equal')
+            for u in [alice, bob, carol]:
+                ExpenseSplit.objects.create(expense=e1, user=u, amount=Decimal('40.00'))
+
+            e2 = Expense.objects.create(event=event, description='Food & Snacks',
+                amount=Decimal('75.00'), paid_by=bob, split_type='equal')
+            for u in [alice, bob, carol]:
+                ExpenseSplit.objects.create(expense=e2, user=u, amount=Decimal('25.00'))
+
+        self.stdout.write(self.style.SUCCESS(
+            f'Demo created! Login: alice/demo1234, bob/demo1234, carol/demo1234\n'
+            f'Room invite code: {room.invite_code}'
+        ))

splitchat/core/migrations/0001_initial.py

@@ -0,0 +1,110 @@
+# Generated by Django 6.0.5 on 2026-05-22 15:23
+
+import django.db.models.deletion
+import uuid
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ChatRoom',
+            fields=[
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
+                ('name', models.CharField(max_length=100)),
+                ('description', models.TextField(blank=True)),
+                ('invite_code', models.CharField(blank=True, max_length=12, unique=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('created_by', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='created_rooms', to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Event',
+            fields=[
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
+                ('title', models.CharField(max_length=200)),
+                ('description', models.TextField(blank=True)),
+                ('location', models.CharField(blank=True, max_length=200)),
+                ('event_date', models.DateTimeField(blank=True, null=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('is_settled', models.BooleanField(default=False)),
+                ('created_by', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='created_events', to=settings.AUTH_USER_MODEL)),
+                ('room', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='events', to='core.chatroom')),
+            ],
+            options={
+                'ordering': ['-created_at'],
+            },
+        ),
+        migrations.CreateModel(
+            name='Expense',
+            fields=[
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
+                ('description', models.CharField(max_length=200)),
+                ('amount', models.DecimalField(decimal_places=2, max_digits=10)),
+                ('split_type', models.CharField(choices=[('equal', 'Equal'), ('custom', 'Custom')], default='equal', max_length=10)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='expenses', to='core.event')),
+                ('paid_by', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='paid_expenses', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'ordering': ['-created_at'],
+            },
+        ),
+        migrations.CreateModel(
+            name='Message',
+            fields=[
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
+                ('content', models.TextField()),
+                ('msg_type', models.CharField(choices=[('chat', 'Chat'), ('system', 'System'), ('event', 'Event'), ('expense', 'Expense')], default='chat', max_length=20)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('room', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='messages', to='core.chatroom')),
+                ('sender', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='messages', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'ordering': ['created_at'],
+            },
+        ),
+        migrations.CreateModel(
+            name='UserProfile',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('display_name', models.CharField(blank=True, max_length=100)),
+                ('avatar_color', models.CharField(default='#6366f1', max_length=7)),
+                ('user', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='profile', to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='ExpenseSplit',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('amount', models.DecimalField(decimal_places=2, max_digits=10)),
+                ('expense', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='splits', to='core.expense')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='expense_splits', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'unique_together': {('expense', 'user')},
+            },
+        ),
+        migrations.CreateModel(
+            name='Membership',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('joined_at', models.DateTimeField(auto_now_add=True)),
+                ('is_active', models.BooleanField(default=True)),
+                ('is_admin', models.BooleanField(default=False)),
+                ('room', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='memberships', to='core.chatroom')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='memberships', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'unique_together': {('user', 'room')},
+            },
+        ),
+    ]

splitchat/core/models.py

@@ -0,0 +1,177 @@
+import uuid
+from decimal import Decimal
+from django.db import models
+from django.contrib.auth.models import User
+from django.utils import timezone
+
+
+class ChatRoom(models.Model):
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    name = models.CharField(max_length=100)
+    description = models.TextField(blank=True)
+    invite_code = models.CharField(max_length=12, unique=True, blank=True)
+    created_by = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, related_name='created_rooms')
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    def save(self, *args, **kwargs):
+        if not self.invite_code:
+            self.invite_code = uuid.uuid4().hex[:8].upper()
+        super().save(*args, **kwargs)
+
+    def __str__(self):
+        return self.name
+
+    @property
+    def member_count(self):
+        return self.memberships.filter(is_active=True).count()
+
+
+class Membership(models.Model):
+    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='memberships')
+    room = models.ForeignKey(ChatRoom, on_delete=models.CASCADE, related_name='memberships')
+    joined_at = models.DateTimeField(auto_now_add=True)
+    is_active = models.BooleanField(default=True)
+    is_admin = models.BooleanField(default=False)
+
+    class Meta:
+        unique_together = ('user', 'room')
+
+    def __str__(self):
+        return f"{self.user.username} in {self.room.name}"
+
+
+class Message(models.Model):
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    room = models.ForeignKey(ChatRoom, on_delete=models.CASCADE, related_name='messages')
+    sender = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, related_name='messages')
+    content = models.TextField()
+    msg_type = models.CharField(max_length=20, default='chat',
+        choices=[('chat', 'Chat'), ('system', 'System'), ('event', 'Event'), ('expense', 'Expense')])
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        ordering = ['created_at']
+
+    def __str__(self):
+        return f"{self.sender}: {self.content[:50]}"
+
+
+class Event(models.Model):
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    room = models.ForeignKey(ChatRoom, on_delete=models.CASCADE, related_name='events')
+    created_by = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, related_name='created_events')
+    title = models.CharField(max_length=200)
+    description = models.TextField(blank=True)
+    location = models.CharField(max_length=200, blank=True)
+    event_date = models.DateTimeField(null=True, blank=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+    is_settled = models.BooleanField(default=False)
+
+    class Meta:
+        ordering = ['-created_at']
+
+    def __str__(self):
+        return self.title
+
+    @property
+    def total_amount(self):
+        return self.expenses.aggregate(total=models.Sum('amount'))['total'] or Decimal('0')
+
+    def compute_balances(self):
+        """Returns dict: {user_id: net_balance} positive=owed, negative=owes"""
+        balances = {}
+        for expense in self.expenses.prefetch_related('splits'):
+            payer_id = expense.paid_by_id
+            balances[payer_id] = balances.get(payer_id, Decimal('0')) + expense.amount
+            for split in expense.splits.all():
+                uid = split.user_id
+                balances[uid] = balances.get(uid, Decimal('0')) - split.amount
+        return balances
+
+    def compute_settlements(self):
+        """Simplify debts: returns list of (debtor_user, creditor_user, amount)"""
+        balances = self.compute_balances()
+        # Fetch users
+        user_ids = list(balances.keys())
+        users = {u.id: u for u in User.objects.filter(id__in=user_ids)}
+
+        debtors = sorted(
+            [(uid, -bal) for uid, bal in balances.items() if bal < -Decimal('0.01')],
+            key=lambda x: -x[1]
+        )
+        creditors = sorted(
+            [(uid, bal) for uid, bal in balances.items() if bal > Decimal('0.01')],
+            key=lambda x: -x[1]
+        )
+
+        settlements = []
+        i, j = 0, 0
+        debtors = [[uid, amt] for uid, amt in debtors]
+        creditors = [[uid, amt] for uid, amt in creditors]
+
+        while i < len(debtors) and j < len(creditors):
+            debtor_id, debt = debtors[i]
+            creditor_id, credit = creditors[j]
+            amount = min(debt, credit)
+            if amount > Decimal('0.01'):
+                settlements.append((users.get(debtor_id), users.get(creditor_id), round(amount, 2)))
+            debtors[i][1] -= amount
+            creditors[j][1] -= amount
+            if debtors[i][1] < Decimal('0.01'):
+                i += 1
+            if creditors[j][1] < Decimal('0.01'):
+                j += 1
+
+        return settlements
+
+
+class Expense(models.Model):
+    SPLIT_EQUAL = 'equal'
+    SPLIT_CUSTOM = 'custom'
+    SPLIT_CHOICES = [(SPLIT_EQUAL, 'Equal'), (SPLIT_CUSTOM, 'Custom')]
+
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    event = models.ForeignKey(Event, on_delete=models.CASCADE, related_name='expenses')
+    description = models.CharField(max_length=200)
+    amount = models.DecimalField(max_digits=10, decimal_places=2)
+    paid_by = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, related_name='paid_expenses')
+    split_type = models.CharField(max_length=10, choices=SPLIT_CHOICES, default=SPLIT_EQUAL)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        ordering = ['-created_at']
+
+    def __str__(self):
+        return f"{self.description}: ${self.amount}"
+
+
+class ExpenseSplit(models.Model):
+    expense = models.ForeignKey(Expense, on_delete=models.CASCADE, related_name='splits')
+    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='expense_splits')
+    amount = models.DecimalField(max_digits=10, decimal_places=2)
+
+    class Meta:
+        unique_together = ('expense', 'user')
+
+    def __str__(self):
+        return f"{self.user.username}: ${self.amount}"
+
+
+class UserProfile(models.Model):
+    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='profile')
+    display_name = models.CharField(max_length=100, blank=True)
+    avatar_color = models.CharField(max_length=7, default='#6366f1')
+
+    def __str__(self):
+        return f"Profile({self.user.username})"
+
+    @property
+    def name(self):
+        return self.display_name or self.user.get_full_name() or self.user.username
+
+    def get_avatar_initials(self):
+        name = self.name
+        parts = name.split()
+        if len(parts) >= 2:
+            return (parts[0][0] + parts[-1][0]).upper()
+        return name[:2].upper()

splitchat/core/routing.py

@@ -0,0 +1,6 @@
+from django.urls import re_path
+from core import consumers
+
+websocket_urlpatterns = [
+    re_path(r'ws/chat/(?P<room_id>[0-9a-f-]+)/$', consumers.ChatConsumer.as_asgi()),
+]

splitchat/core/signals.py

@@ -0,0 +1,15 @@
+from django.db.models.signals import post_save
+from django.contrib.auth.models import User
+from django.dispatch import receiver
+from .models import UserProfile
+
+AVATAR_COLORS = [
+    '#6366f1', '#8b5cf6', '#ec4899', '#f43f5e',
+    '#f97316', '#eab308', '#22c55e', '#14b8a6', '#3b82f6'
+]
+
+@receiver(post_save, sender=User)
+def create_user_profile(sender, instance, created, **kwargs):
+    if created:
+        color = AVATAR_COLORS[instance.id % len(AVATAR_COLORS)]
+        UserProfile.objects.get_or_create(user=instance, defaults={'avatar_color': color})

splitchat/core/templates/core/auth.html

@@ -0,0 +1,43 @@
+{% extends 'core/base.html' %}
+{% block title %}{% if mode == 'login' %}Sign In{% else %}Sign Up{% endif %} – SplitChat{% endblock %}
+
+{% block body %}
+<div style="min-height:100vh;display:flex;align-items:center;justify-content:center;background:var(--bg);padding:20px;">
+  <div style="width:100%;max-width:420px;">
+    <div style="text-align:center;margin-bottom:32px;">
+      <div style="font-size:40px;margin-bottom:12px;">💬</div>
+      <div class="logo" style="justify-content:center;font-size:24px;margin-bottom:8px;">SplitChat</div>
+      <p class="text-muted text-sm">Chat, plan events, split costs — together.</p>
+    </div>
+    <div class="card" style="padding:32px;">
+      <h2 style="font-size:20px;font-weight:700;margin-bottom:24px;">
+        {% if mode == 'login' %}Welcome back{% else %}Create account{% endif %}
+      </h2>
+      <form method="post">
+        {% csrf_token %}
+        {% for field in form %}
+        <div class="form-group">
+          <label>{{ field.label }}</label>
+          {{ field }}
+          {% if field.errors %}<div class="error-list">{{ field.errors.0 }}</div>{% endif %}
+        </div>
+        {% endfor %}
+        {% if form.non_field_errors %}
+        <div class="error-list" style="margin-bottom:12px;">{{ form.non_field_errors.0 }}</div>
+        {% endif %}
+        <button type="submit" class="btn btn-primary" style="width:100%;justify-content:center;margin-top:8px;">
+          {% if mode == 'login' %}Sign In{% else %}Create Account{% endif %}
+        </button>
+      </form>
+      <div class="divider"></div>
+      <p class="text-sm text-muted" style="text-align:center;">
+        {% if mode == 'login' %}
+          Don't have an account? <a href="{% url 'signup' %}">Sign up free</a>
+        {% else %}
+          Already have an account? <a href="{% url 'login' %}">Sign in</a>
+        {% endif %}
+      </p>
+    </div>
+  </div>
+</div>
+{% endblock %}

splitchat/core/templates/core/base.html

@@ -0,0 +1,292 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>{% block title %}SplitChat{% endblock %}</title>
+<link rel="preconnect" href="https://fonts.googleapis.com">
+<link href="https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap" rel="stylesheet">
+<style>
+/* ── Reset & Variables ── */
+*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
+:root {
+  --bg: #0d0f14;
+  --bg2: #13161d;
+  --bg3: #1a1e27;
+  --bg4: #1f2433;
+  --border: rgba(255,255,255,0.07);
+  --border2: rgba(255,255,255,0.12);
+  --text: #e8eaf0;
+  --text2: #9aa0b2;
+  --text3: #5c6375;
+  --accent: #6366f1;
+  --accent2: #818cf8;
+  --accent-glow: rgba(99,102,241,0.15);
+  --green: #22c55e;
+  --red: #f43f5e;
+  --amber: #f59e0b;
+  --radius: 12px;
+  --radius-sm: 8px;
+  --shadow: 0 4px 24px rgba(0,0,0,0.4);
+  --shadow-lg: 0 8px 48px rgba(0,0,0,0.6);
+  --font: 'Space Grotesk', sans-serif;
+  --mono: 'JetBrains Mono', monospace;
+  --sidebar-w: 260px;
+}
+
+html, body { height: 100%; font-family: var(--font); background: var(--bg); color: var(--text); font-size: 15px; line-height: 1.6; }
+
+a { color: var(--accent2); text-decoration: none; }
+a:hover { color: var(--text); }
+
+input, textarea, select {
+  font-family: var(--font);
+  background: var(--bg3);
+  border: 1px solid var(--border2);
+  color: var(--text);
+  border-radius: var(--radius-sm);
+  padding: 10px 14px;
+  font-size: 14px;
+  width: 100%;
+  transition: border-color 0.2s, box-shadow 0.2s;
+  outline: none;
+}
+input:focus, textarea:focus, select:focus {
+  border-color: var(--accent);
+  box-shadow: 0 0 0 3px var(--accent-glow);
+}
+input[type="checkbox"], input[type="radio"] { width: auto; }
+label { display: block; font-size: 13px; color: var(--text2); margin-bottom: 5px; font-weight: 500; }
+
+button, .btn {
+  display: inline-flex; align-items: center; gap: 6px;
+  font-family: var(--font); font-size: 14px; font-weight: 600;
+  padding: 10px 20px; border-radius: var(--radius-sm);
+  border: none; cursor: pointer; transition: all 0.2s;
+  text-decoration: none;
+}
+.btn-primary {
+  background: var(--accent); color: #fff;
+}
+.btn-primary:hover { background: var(--accent2); color: #fff; transform: translateY(-1px); box-shadow: 0 4px 16px var(--accent-glow); }
+.btn-secondary {
+  background: var(--bg4); color: var(--text2); border: 1px solid var(--border2);
+}
+.btn-secondary:hover { background: var(--bg3); color: var(--text); }
+.btn-ghost { background: transparent; color: var(--text2); }
+.btn-ghost:hover { background: var(--bg3); color: var(--text); }
+.btn-danger { background: var(--red); color: #fff; }
+.btn-success { background: var(--green); color: #fff; }
+.btn-sm { padding: 6px 14px; font-size: 13px; }
+
+.card {
+  background: var(--bg2);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  padding: 20px;
+}
+
+.badge {
+  display: inline-block;
+  padding: 2px 10px;
+  border-radius: 20px;
+  font-size: 12px;
+  font-weight: 600;
+}
+.badge-accent { background: var(--accent-glow); color: var(--accent2); border: 1px solid rgba(99,102,241,0.3); }
+.badge-green { background: rgba(34,197,94,0.1); color: var(--green); border: 1px solid rgba(34,197,94,0.3); }
+.badge-red { background: rgba(244,63,94,0.1); color: var(--red); border: 1px solid rgba(244,63,94,0.3); }
+.badge-amber { background: rgba(245,158,11,0.1); color: var(--amber); border: 1px solid rgba(245,158,11,0.3); }
+
+.avatar {
+  display: inline-flex; align-items: center; justify-content: center;
+  border-radius: 50%; font-weight: 700; font-size: 12px; color: #fff; flex-shrink: 0;
+}
+.avatar-sm { width: 28px; height: 28px; font-size: 11px; }
+.avatar-md { width: 36px; height: 36px; font-size: 13px; }
+.avatar-lg { width: 48px; height: 48px; font-size: 16px; }
+
+.divider { height: 1px; background: var(--border); margin: 16px 0; }
+
+/* Messages */
+.messages-container { position: fixed; top: 20px; right: 20px; z-index: 1000; display: flex; flex-direction: column; gap: 8px; }
+.message-toast {
+  background: var(--bg3); border: 1px solid var(--border2);
+  padding: 12px 18px; border-radius: var(--radius-sm);
+  font-size: 14px; box-shadow: var(--shadow);
+  animation: slideIn 0.3s ease;
+  max-width: 320px;
+}
+.message-toast.success { border-left: 3px solid var(--green); }
+.message-toast.error { border-left: 3px solid var(--red); }
+.message-toast.info { border-left: 3px solid var(--accent); }
+@keyframes slideIn { from { opacity: 0; transform: translateX(20px); } to { opacity: 1; transform: translateX(0); } }
+
+/* Layout */
+.app-layout { display: flex; height: 100vh; overflow: hidden; }
+.sidebar {
+  width: var(--sidebar-w); flex-shrink: 0;
+  background: var(--bg2); border-right: 1px solid var(--border);
+  display: flex; flex-direction: column;
+  overflow-y: auto;
+}
+.main-content { flex: 1; overflow-y: auto; }
+
+.sidebar-header {
+  padding: 20px;
+  border-bottom: 1px solid var(--border);
+}
+.logo {
+  font-size: 18px; font-weight: 700;
+  background: linear-gradient(135deg, var(--accent2), #c084fc);
+  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
+  display: flex; align-items: center; gap: 8px;
+}
+.logo-icon { font-size: 22px; -webkit-text-fill-color: initial; }
+
+.sidebar-nav { padding: 12px 8px; flex: 1; }
+.nav-section-title {
+  font-size: 11px; text-transform: uppercase; letter-spacing: 0.1em;
+  color: var(--text3); padding: 8px 12px; margin-top: 8px;
+}
+.nav-item {
+  display: flex; align-items: center; gap: 10px;
+  padding: 9px 12px; border-radius: var(--radius-sm);
+  color: var(--text2); font-size: 14px; font-weight: 500;
+  transition: all 0.15s; cursor: pointer;
+  text-decoration: none;
+  margin-bottom: 2px;
+}
+.nav-item:hover, .nav-item.active {
+  background: var(--bg3); color: var(--text);
+}
+.nav-item .icon { font-size: 16px; width: 20px; text-align: center; }
+.nav-item .count {
+  margin-left: auto; font-size: 11px; background: var(--bg4);
+  padding: 1px 7px; border-radius: 10px; color: var(--text3);
+}
+
+.sidebar-footer {
+  padding: 12px;
+  border-top: 1px solid var(--border);
+}
+.user-pill {
+  display: flex; align-items: center; gap: 10px;
+  padding: 8px; border-radius: var(--radius-sm);
+  background: var(--bg3);
+}
+.user-pill .info { flex: 1; min-width: 0; }
+.user-pill .name { font-size: 13px; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
+.user-pill .role { font-size: 11px; color: var(--text3); }
+
+/* Page header */
+.page-header {
+  padding: 32px 40px 0;
+  display: flex; align-items: flex-start; justify-content: space-between;
+  flex-wrap: wrap; gap: 16px;
+}
+.page-title { font-size: 26px; font-weight: 700; }
+.page-subtitle { color: var(--text2); font-size: 14px; margin-top: 4px; }
+
+.page-body { padding: 24px 40px 40px; }
+
+/* Form styles */
+.form-group { margin-bottom: 16px; }
+.form-card { max-width: 520px; margin: 40px auto; }
+.error-list { color: var(--red); font-size: 13px; margin-top: 4px; }
+
+/* Grid */
+.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
+.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
+
+/* Misc */
+.text-muted { color: var(--text2); }
+.text-sm { font-size: 13px; }
+.text-xs { font-size: 12px; }
+.font-mono { font-family: var(--mono); }
+.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.flex { display: flex; }
+.flex-center { display: flex; align-items: center; }
+.gap-2 { gap: 8px; }
+.gap-3 { gap: 12px; }
+.mt-1 { margin-top: 4px; }
+.mt-2 { margin-top: 8px; }
+.mt-3 { margin-top: 12px; }
+.mb-3 { margin-bottom: 12px; }
+
+/* Scrollbar */
+::-webkit-scrollbar { width: 6px; height: 6px; }
+::-webkit-scrollbar-track { background: transparent; }
+::-webkit-scrollbar-thumb { background: var(--bg4); border-radius: 3px; }
+::-webkit-scrollbar-thumb:hover { background: var(--text3); }
+</style>
+{% block extra_css %}{% endblock %}
+</head>
+<body>
+{% if messages %}
+<div class="messages-container" id="toastContainer">
+  {% for msg in messages %}
+  <div class="message-toast {{ msg.tags }}">{{ msg }}</div>
+  {% endfor %}
+</div>
+{% endif %}
+
+{% block body %}
+<div class="app-layout">
+  {% if user.is_authenticated %}
+  <aside class="sidebar">
+    <div class="sidebar-header">
+      <div class="logo"><span class="logo-icon">💬</span> SplitChat</div>
+    </div>
+    <nav class="sidebar-nav">
+      <a href="{% url 'dashboard' %}" class="nav-item {% if request.resolver_match.url_name == 'dashboard' %}active{% endif %}">
+        <span class="icon">⊞</span> Dashboard
+      </a>
+      <a href="{% url 'room_create' %}" class="nav-item">
+        <span class="icon">+</span> New Room
+      </a>
+      <a href="{% url 'room_join' %}" class="nav-item">
+        <span class="icon">→</span> Join Room
+      </a>
+      {% if rooms %}
+      <div class="nav-section-title">Your Rooms</div>
+      {% for room in rooms %}
+      <a href="{% url 'room_detail' room_id=room.id %}" 
+         class="nav-item {% if current_room and current_room.id == room.id %}active{% endif %}">
+        <span class="icon">#</span>
+        <span class="truncate">{{ room.name }}</span>
+        <span class="count">{{ room.member_count }}</span>
+      </a>
+      {% endfor %}
+      {% endif %}
+    </nav>
+    <div class="sidebar-footer">
+      {% if user.profile %}
+      <div class="user-pill">
+        <div class="avatar avatar-sm" style="background:{{ user.profile.avatar_color }}">{{ user.profile.get_avatar_initials }}</div>
+        <div class="info">
+          <div class="name">{{ user.profile.name }}</div>
+          <div class="role">@{{ user.username }}</div>
+        </div>
+        <a href="{% url 'logout' %}" class="btn btn-ghost btn-sm" title="Log out">↩</a>
+      </div>
+      {% endif %}
+    </div>
+  </aside>
+  {% endif %}
+  <main class="main-content">
+    {% block content %}{% endblock %}
+  </main>
+</div>
+{% endblock %}
+
+<script>
+// Auto-dismiss toasts
+setTimeout(() => {
+  const toasts = document.querySelectorAll('.message-toast');
+  toasts.forEach(t => { t.style.opacity = '0'; t.style.transition = 'opacity 0.4s'; setTimeout(() => t.remove(), 400); });
+}, 3500);
+</script>
+{% block extra_js %}{% endblock %}
+</body>
+</html>

splitchat/core/templates/core/dashboard.html

@@ -0,0 +1,110 @@
+{% extends 'core/base.html' %}
+{% block title %}Dashboard – SplitChat{% endblock %}
+{% block content %}
+{% with rooms=rooms %}
+
+<div class="page-header">
+  <div>
+    <h1 class="page-title">Dashboard</h1>
+    <p class="page-subtitle">Good to see you, {{ profile.name }} 👋</p>
+  </div>
+  <div class="flex gap-2">
+    <a href="{% url 'room_join' %}" class="btn btn-secondary">Join Room</a>
+    <a href="{% url 'room_create' %}" class="btn btn-primary">+ New Room</a>
+  </div>
+</div>
+
+<div class="page-body">
+
+  <!-- Balance Overview -->
+  <div class="grid-3" style="margin-bottom:28px;">
+    <div class="card" style="border-color:{% if net_balance >= 0 %}rgba(34,197,94,0.2){% else %}rgba(244,63,94,0.2){% endif %};">
+      <div class="text-xs text-muted" style="text-transform:uppercase;letter-spacing:.08em;margin-bottom:8px;">Net Balance</div>
+      <div style="font-size:28px;font-weight:700;color:{% if net_balance >= 0 %}var(--green){% else %}var(--red){% endif %};">
+        {% if net_balance >= 0 %}+{% endif %}${{ net_balance|floatformat:2 }}
+      </div>
+      <div class="text-xs text-muted mt-1">{% if net_balance >= 0 %}You're in the green{% else %}You have outstanding debts{% endif %}</div>
+    </div>
+    <div class="card">
+      <div class="text-xs text-muted" style="text-transform:uppercase;letter-spacing:.08em;margin-bottom:8px;">Owed to You</div>
+      <div style="font-size:28px;font-weight:700;color:var(--green);">+${{ total_owed|floatformat:2 }}</div>
+      <div class="text-xs text-muted mt-1">Others owe you this</div>
+    </div>
+    <div class="card">
+      <div class="text-xs text-muted" style="text-transform:uppercase;letter-spacing:.08em;margin-bottom:8px;">You Owe</div>
+      <div style="font-size:28px;font-weight:700;color:{% if total_owing > 0 %}var(--red){% else %}var(--text2){% endif %};">${{ total_owing|floatformat:2 }}</div>
+      <div class="text-xs text-muted mt-1">Across all unsettled events</div>
+    </div>
+  </div>
+
+  <div class="grid-2" style="gap:28px;align-items:start;">
+
+    <!-- Rooms -->
+    <div>
+      <div class="flex-center gap-2" style="margin-bottom:14px;justify-content:space-between;">
+        <h2 style="font-size:16px;font-weight:700;">Your Rooms</h2>
+        <a href="{% url 'room_create' %}" class="btn btn-ghost btn-sm">+ New</a>
+      </div>
+      {% if rooms %}
+        {% for room in rooms %}
+        <a href="{% url 'room_detail' room_id=room.id %}" style="text-decoration:none;">
+          <div class="card" style="margin-bottom:10px;transition:all .2s;cursor:pointer;" 
+               onmouseover="this.style.borderColor='var(--border2)';this.style.transform='translateY(-1px)'"
+               onmouseout="this.style.borderColor='var(--border)';this.style.transform='none'">
+            <div class="flex-center gap-3">
+              <div style="width:40px;height:40px;border-radius:10px;background:var(--accent-glow);display:flex;align-items:center;justify-content:center;font-size:18px;flex-shrink:0;">#</div>
+              <div style="flex:1;min-width:0;">
+                <div style="font-weight:600;font-size:15px;">{{ room.name }}</div>
+                {% if room.description %}
+                <div class="text-xs text-muted truncate">{{ room.description }}</div>
+                {% endif %}
+              </div>
+              <div class="text-xs text-muted">{{ room.member_count }} member{{ room.member_count|pluralize }}</div>
+            </div>
+          </div>
+        </a>
+        {% endfor %}
+      {% else %}
+        <div class="card" style="text-align:center;padding:40px;color:var(--text3);">
+          <div style="font-size:32px;margin-bottom:8px;">💬</div>
+          <div>No rooms yet.</div>
+          <a href="{% url 'room_create' %}" class="btn btn-primary btn-sm" style="margin-top:12px;">Create your first room</a>
+        </div>
+      {% endif %}
+    </div>
+
+    <!-- Upcoming Events -->
+    <div>
+      <div class="flex-center gap-2" style="margin-bottom:14px;justify-content:space-between;">
+        <h2 style="font-size:16px;font-weight:700;">Upcoming Events</h2>
+      </div>
+      {% if upcoming_events %}
+        {% for event in upcoming_events %}
+        <a href="{% url 'event_detail' room_id=event.room.id event_id=event.id %}" style="text-decoration:none;">
+          <div class="card" style="margin-bottom:10px;transition:all .2s;"
+               onmouseover="this.style.borderColor='var(--border2)';this.style.transform='translateY(-1px)'"
+               onmouseout="this.style.borderColor='var(--border)';this.style.transform='none'">
+            <div class="flex-center" style="justify-content:space-between;margin-bottom:6px;">
+              <div style="font-weight:600;font-size:15px;">{{ event.title }}</div>
+              <span class="badge badge-accent">{{ event.room.name }}</span>
+            </div>
+            <div class="flex-center gap-2 text-xs text-muted">
+              {% if event.location %}<span>📍 {{ event.location }}</span>{% endif %}
+              {% if event.event_date %}<span>🗓 {{ event.event_date|date:"M j, g:i A" }}</span>{% endif %}
+              <span>💰 ${{ event.total_amount|floatformat:2 }}</span>
+            </div>
+          </div>
+        </a>
+        {% endfor %}
+      {% else %}
+        <div class="card" style="text-align:center;padding:40px;color:var(--text3);">
+          <div style="font-size:32px;margin-bottom:8px;">📅</div>
+          <div>No upcoming events.</div>
+        </div>
+      {% endif %}
+    </div>
+
+  </div>
+</div>
+{% endwith %}
+{% endblock %}

splitchat/core/templates/core/event_detail.html

@@ -0,0 +1,219 @@
+{% extends 'core/base.html' %}
+{% block title %}{{ event.title }} – SplitChat{% endblock %}
+
+{% block extra_css %}
+<style>
+.expense-row {
+  padding: 14px 0; border-bottom: 1px solid var(--border);
+  display: flex; align-items: flex-start; justify-content: space-between; gap: 12px;
+}
+.expense-row:last-child { border-bottom: none; }
+
+.settlement-row {
+  display: flex; align-items: center; gap: 10px;
+  padding: 10px 14px; background: var(--bg3);
+  border-radius: var(--radius-sm); margin-bottom: 8px;
+  font-size: 14px;
+}
+
+.balance-bar-wrap { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; }
+.balance-bar { flex: 1; height: 6px; border-radius: 3px; background: var(--bg4); overflow: hidden; }
+.balance-bar-fill { height: 100%; border-radius: 3px; transition: width .4s; }
+
+.split-participant { display: flex; align-items: center; gap: 6px; font-size: 13px; color: var(--text2); margin-top: 4px; }
+
+.modal-overlay {
+  position: fixed; inset: 0; background: rgba(0,0,0,0.7);
+  display: flex; align-items: center; justify-content: center;
+  z-index: 500; padding: 20px;
+}
+.modal {
+  background: var(--bg2); border: 1px solid var(--border2);
+  border-radius: var(--radius); padding: 28px;
+  width: 100%; max-width: 520px; max-height: 90vh; overflow-y: auto;
+  box-shadow: var(--shadow-lg);
+}
+.modal h3 { font-size: 18px; font-weight: 700; margin-bottom: 20px; }
+</style>
+{% endblock %}
+
+{% block content %}
+{% with current_room=room %}
+<div class="page-header">
+  <div>
+    <div class="flex-center gap-2" style="margin-bottom:6px;">
+      <a href="{% url 'room_detail' room_id=room.id %}" class="text-muted text-sm">#{{ room.name }}</a>
+      <span class="text-muted text-sm">/</span>
+      <span class="text-sm">Events</span>
+    </div>
+    <h1 class="page-title">{{ event.title }}</h1>
+    <div class="flex-center gap-3 text-sm text-muted mt-1">
+      {% if event.location %}<span>📍 {{ event.location }}</span>{% endif %}
+      {% if event.event_date %}<span>🗓 {{ event.event_date|date:"M j, Y · g:i A" }}</span>{% endif %}
+      <span>Created by {{ event.created_by.username }}</span>
+      {% if event.is_settled %}<span class="badge badge-green">✓ Settled</span>{% endif %}
+    </div>
+    {% if event.description %}<p class="text-sm text-muted" style="margin-top:8px;">{{ event.description }}</p>{% endif %}
+  </div>
+  <div class="flex gap-2">
+    {% if not event.is_settled %}
+    <button class="btn btn-secondary" onclick="document.getElementById('expenseModal').style.display='flex'">+ Add Expense</button>
+    <form method="post" action="{% url 'event_settle' room_id=room.id event_id=event.id %}" style="display:inline;">
+      {% csrf_token %}
+      <button type="submit" class="btn btn-success" onclick="return confirm('Mark this event as settled?')">✓ Settle Up</button>
+    </form>
+    {% endif %}
+  </div>
+</div>
+
+<div class="page-body">
+  <div style="display:grid;grid-template-columns:1fr 340px;gap:24px;align-items:start;">
+
+    <!-- LEFT: Expenses -->
+    <div>
+      <div class="card" style="margin-bottom:20px;">
+        <div class="flex-center" style="justify-content:space-between;margin-bottom:16px;">
+          <h2 style="font-size:16px;font-weight:700;">Expenses</h2>
+          <div style="font-size:22px;font-weight:700;">Total: ${{ event.total_amount|floatformat:2 }}</div>
+        </div>
+
+        {% if expenses %}
+          {% for expense in expenses %}
+          <div class="expense-row">
+            <div style="flex:1;">
+              <div style="font-weight:600;font-size:15px;">{{ expense.description }}</div>
+              <div class="text-sm text-muted">Paid by
+                <strong style="color:var(--text);">{{ expense.paid_by.username }}</strong>
+                · {{ expense.get_split_type_display }} split
+              </div>
+              <div style="margin-top:6px;">
+                {% for split in expense.splits.all %}
+                <div class="split-participant">
+                  <div class="avatar avatar-sm" style="background:{% if split.user.profile %}{{ split.user.profile.avatar_color }}{% else %}#6366f1{% endif %};">
+                    {% if split.user.profile %}{{ split.user.profile.get_avatar_initials }}{% else %}??{% endif %}
+                  </div>
+                  {% if split.user.profile %}{{ split.user.profile.name }}{% else %}{{ split.user.username }}{% endif %}
+                  <span style="color:var(--text3);">– ${{ split.amount }}</span>
+                </div>
+                {% endfor %}
+              </div>
+            </div>
+            <div style="text-align:right;flex-shrink:0;">
+              <div style="font-size:20px;font-weight:700;">${{ expense.amount }}</div>
+              <div class="text-xs text-muted">{{ expense.created_at|date:"M j" }}</div>
+            </div>
+          </div>
+          {% endfor %}
+        {% else %}
+          <div style="text-align:center;padding:40px;color:var(--text3);">
+            <div style="font-size:36px;margin-bottom:8px;">💸</div>
+            <div>No expenses yet.</div>
+            {% if not event.is_settled %}
+            <button class="btn btn-primary btn-sm" style="margin-top:12px;" onclick="document.getElementById('expenseModal').style.display='flex'">Add first expense</button>
+            {% endif %}
+          </div>
+        {% endif %}
+      </div>
+    </div>
+
+    <!-- RIGHT: Balances & Settlement -->
+    <div>
+      <!-- Balances -->
+      <div class="card" style="margin-bottom:16px;">
+        <h3 style="font-size:15px;font-weight:700;margin-bottom:16px;">Balances</h3>
+        {% if balance_display %}
+          {% for item in balance_display %}
+          <div class="balance-bar-wrap">
+            <div class="avatar avatar-sm" style="background:{% if item.user.profile %}{{ item.user.profile.avatar_color }}{% else %}#6366f1{% endif %};">
+              {% if item.user.profile %}{{ item.user.profile.get_avatar_initials }}{% else %}??{% endif %}
+            </div>
+            <div style="flex:1;min-width:0;">
+              <div class="flex-center" style="justify-content:space-between;margin-bottom:4px;">
+                <span class="text-sm" style="font-weight:500;">{% if item.user.profile %}{{ item.user.profile.name }}{% else %}{{ item.user.username }}{% endif %}</span>
+                <span class="text-sm" style="color:{% if item.amount >= 0 %}var(--green){% else %}var(--red){% endif %};font-weight:600;">
+                  {% if item.amount >= 0 %}+{% endif %}${{ item.amount|floatformat:2 }}
+                </span>
+              </div>
+            </div>
+          </div>
+          {% endfor %}
+        {% else %}
+          <div class="text-sm text-muted">No expenses to balance yet.</div>
+        {% endif %}
+      </div>
+
+      <!-- Settlements -->
+      <div class="card">
+        <h3 style="font-size:15px;font-weight:700;margin-bottom:16px;">Settlement Plan</h3>
+        {% if settlements %}
+          {% for debtor, creditor, amount in settlements %}
+          <div class="settlement-row">
+            <div class="avatar avatar-sm" style="background:{% if debtor.profile %}{{ debtor.profile.avatar_color }}{% else %}#6366f1{% endif %};">
+              {% if debtor.profile %}{{ debtor.profile.get_avatar_initials }}{% else %}??{% endif %}
+            </div>
+            <div style="flex:1;">
+              <strong>{% if debtor.profile %}{{ debtor.profile.name }}{% else %}{{ debtor.username }}{% endif %}</strong>
+              owes
+              <strong>{% if creditor.profile %}{{ creditor.profile.name }}{% else %}{{ creditor.username }}{% endif %}</strong>
+            </div>
+            <div style="font-weight:700;color:var(--amber);">${{ amount }}</div>
+          </div>
+          {% endfor %}
+        {% elif expenses %}
+          <div class="text-sm" style="color:var(--green);">✓ All squared up! No transfers needed.</div>
+        {% else %}
+          <div class="text-sm text-muted">Add expenses to see who owes whom.</div>
+        {% endif %}
+      </div>
+    </div>
+
+  </div>
+</div>
+
+<!-- ADD EXPENSE MODAL -->
+<div class="modal-overlay" id="expenseModal" style="display:none;" onclick="if(event.target===this)this.style.display='none'">
+  <div class="modal">
+    <h3>Add Expense</h3>
+    <form method="post" action="{% url 'expense_create' room_id=room.id event_id=event.id %}">
+      {% csrf_token %}
+      {% for field in expense_form %}
+        {% if field.name == 'split_type' %}
+        <div class="form-group">
+          <label>{{ field.label }}</label>
+          <div class="flex gap-3" style="margin-top:4px;">
+            {% for choice in field %}
+            <label style="display:flex;align-items:center;gap:6px;cursor:pointer;margin-bottom:0;">
+              {{ choice.tag }} <span style="font-size:14px;color:var(--text);">{{ choice.choice_label }}</span>
+            </label>
+            {% endfor %}
+          </div>
+        </div>
+        {% elif field.name == 'participants' %}
+        <div class="form-group">
+          <label>{{ field.label }}</label>
+          <div style="display:grid;grid-template-columns:1fr 1fr;gap:6px;margin-top:6px;">
+            {% for choice in field %}
+            <label style="display:flex;align-items:center;gap:8px;padding:8px 10px;background:var(--bg3);border-radius:var(--radius-sm);cursor:pointer;margin-bottom:0;font-size:14px;color:var(--text);">
+              {{ choice.tag }} {{ choice.choice_label }}
+            </label>
+            {% endfor %}
+          </div>
+          {% if field.errors %}<div class="error-list">{{ field.errors.0 }}</div>{% endif %}
+        </div>
+        {% else %}
+        <div class="form-group">
+          <label>{{ field.label }}</label>
+          {{ field }}
+          {% if field.errors %}<div class="error-list">{{ field.errors.0 }}</div>{% endif %}
+        </div>
+        {% endif %}
+      {% endfor %}
+      <div class="flex gap-2" style="margin-top:16px;">
+        <button type="submit" class="btn btn-primary">Add Expense</button>
+        <button type="button" class="btn btn-secondary" onclick="document.getElementById('expenseModal').style.display='none'">Cancel</button>
+      </div>
+    </form>
+  </div>
+</div>
+{% endwith %}
+{% endblock %}

splitchat/core/templates/core/event_form.html

@@ -0,0 +1,32 @@
+{% extends 'core/base.html' %}
+{% block title %}Create Event – SplitChat{% endblock %}
+{% block content %}
+{% with current_room=room %}
+<div class="page-header">
+  <div>
+    <h1 class="page-title">Create Event</h1>
+    <p class="page-subtitle">in <a href="{% url 'room_detail' room_id=room.id %}">#{{ room.name }}</a></p>
+  </div>
+</div>
+<div class="page-body">
+  <div style="max-width:520px;">
+    <div class="card">
+      <form method="post">
+        {% csrf_token %}
+        {% for field in form %}
+        <div class="form-group">
+          <label>{{ field.label }}</label>
+          {{ field }}
+          {% if field.errors %}<div class="error-list">{{ field.errors.0 }}</div>{% endif %}
+        </div>
+        {% endfor %}
+        <div class="flex gap-2" style="margin-top:8px;">
+          <button type="submit" class="btn btn-primary">Create Event</button>
+          <a href="{% url 'room_detail' room_id=room.id %}" class="btn btn-secondary">Cancel</a>
+        </div>
+      </form>
+    </div>
+  </div>
+</div>
+{% endwith %}
+{% endblock %}

splitchat/core/templates/core/room_detail.html

@@ -0,0 +1,326 @@
+{% extends 'core/base.html' %}
+{% block title %}#{{ room.name }} – SplitChat{% endblock %}
+
+{% block extra_css %}
+<style>
+.room-layout { display: flex; height: 100%; overflow: hidden; }
+.chat-panel { flex: 1; display: flex; flex-direction: column; min-width: 0; }
+.chat-header {
+  padding: 16px 24px; border-bottom: 1px solid var(--border);
+  display: flex; align-items: center; justify-content: space-between;
+  background: var(--bg2); flex-shrink: 0;
+}
+.chat-messages {
+  flex: 1; overflow-y: auto; padding: 20px 24px;
+  display: flex; flex-direction: column; gap: 2px;
+}
+.chat-input-area {
+  padding: 16px 24px; border-top: 1px solid var(--border);
+  background: var(--bg2); flex-shrink: 0;
+}
+.chat-input-row { display: flex; gap: 10px; align-items: flex-end; }
+.chat-input-row textarea {
+  flex: 1; resize: none; min-height: 42px; max-height: 120px;
+  padding: 10px 14px; line-height: 1.4;
+}
+.send-btn {
+  width: 42px; height: 42px; border-radius: var(--radius-sm);
+  background: var(--accent); border: none; cursor: pointer;
+  display: flex; align-items: center; justify-content: center;
+  font-size: 18px; flex-shrink: 0; transition: all .15s;
+}
+.send-btn:hover { background: var(--accent2); transform: scale(1.05); }
+
+.msg-row { display: flex; gap: 10px; padding: 3px 0; }
+.msg-row.own { flex-direction: row-reverse; }
+.msg-bubble {
+  max-width: 72%; padding: 9px 14px;
+  border-radius: 16px; font-size: 14px; line-height: 1.5;
+  word-break: break-word;
+}
+.msg-bubble.other { background: var(--bg3); border-radius: 4px 16px 16px 16px; }
+.msg-bubble.own { background: var(--accent); color: #fff; border-radius: 16px 4px 16px 16px; }
+.msg-bubble.system {
+  background: transparent; color: var(--text3); font-size: 12px;
+  font-style: italic; text-align: center; max-width: 100%; padding: 4px 0;
+}
+.msg-meta { font-size: 11px; color: var(--text3); margin-top: 2px; }
+.msg-sender { font-size: 12px; font-weight: 600; color: var(--text2); margin-bottom: 2px; }
+
+/* Right panel */
+.room-sidebar {
+  width: 280px; flex-shrink: 0;
+  border-left: 1px solid var(--border);
+  background: var(--bg2);
+  display: flex; flex-direction: column;
+  overflow-y: auto;
+}
+.panel-section { padding: 16px; border-bottom: 1px solid var(--border); }
+.panel-title { font-size: 12px; text-transform: uppercase; letter-spacing: .08em; color: var(--text3); margin-bottom: 12px; font-weight: 600; }
+.member-row { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
+.member-name { font-size: 13px; font-weight: 500; }
+
+.event-card {
+  padding: 10px 12px; background: var(--bg3);
+  border-radius: var(--radius-sm); margin-bottom: 8px;
+  border: 1px solid var(--border); transition: all .15s;
+  text-decoration: none; display: block; color: inherit;
+}
+.event-card:hover { border-color: var(--accent); color: inherit; }
+.event-title { font-size: 13px; font-weight: 600; }
+.event-meta { font-size: 11px; color: var(--text3); margin-top: 3px; }
+
+.invite-box {
+  background: var(--bg3); border-radius: var(--radius-sm);
+  padding: 10px 12px; display: flex; align-items: center; gap: 8px;
+}
+.invite-code {
+  font-family: var(--mono); font-size: 15px; font-weight: 600;
+  letter-spacing: .12em; color: var(--accent2); flex: 1;
+}
+
+/* Online indicator */
+.online-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--green); flex-shrink: 0; }
+
+/* Typing indicator */
+.typing-indicator { font-size: 12px; color: var(--text3); min-height: 18px; padding: 0 24px 4px; }
+</style>
+{% endblock %}
+
+{% block content %}
+{% with current_room=room %}
+<div class="room-layout" style="height:100vh;">
+
+  <!-- CHAT PANEL -->
+  <div class="chat-panel">
+    <div class="chat-header">
+      <div class="flex-center gap-3">
+        <div style="font-size:20px;">#</div>
+        <div>
+          <div style="font-weight:700;font-size:16px;">{{ room.name }}</div>
+          {% if room.description %}<div class="text-xs text-muted">{{ room.description }}</div>{% endif %}
+        </div>
+      </div>
+      <div class="flex-center gap-2">
+        <span class="badge badge-accent">{{ members.count }} member{{ members.count|pluralize }}</span>
+        <a href="{% url 'event_create' room_id=room.id %}" class="btn btn-primary btn-sm">+ Event</a>
+      </div>
+    </div>
+
+    <div class="chat-messages" id="chatMessages">
+      {% for msg in messages %}
+        {% if msg.msg_type == 'system' or msg.msg_type == 'event' or msg.msg_type == 'expense' %}
+          <div class="msg-row" style="justify-content:center;">
+            <div class="msg-bubble system">{{ msg.content }}</div>
+          </div>
+        {% else %}
+          <div class="msg-row {% if msg.sender == user %}own{% endif %}" data-msg-id="{{ msg.id }}">
+            {% if msg.sender != user %}
+            <div class="avatar avatar-sm" style="background:{% if msg.sender.profile %}{{ msg.sender.profile.avatar_color }}{% else %}#6366f1{% endif %};margin-top:4px;">
+              {% if msg.sender.profile %}{{ msg.sender.profile.get_avatar_initials }}{% else %}?{% endif %}
+            </div>
+            {% endif %}
+            <div>
+              {% if msg.sender != user %}
+              <div class="msg-sender">{% if msg.sender.profile %}{{ msg.sender.profile.name }}{% else %}{{ msg.sender.username }}{% endif %}</div>
+              {% endif %}
+              <div class="msg-bubble {% if msg.sender == user %}own{% else %}other{% endif %}">{{ msg.content }}</div>
+              <div class="msg-meta {% if msg.sender == user %}" style="text-align:right{% endif %}">{{ msg.created_at|time:"H:i" }}</div>
+            </div>
+          </div>
+        {% endif %}
+      {% empty %}
+        <div style="text-align:center;color:var(--text3);margin:auto;padding:40px 0;">
+          <div style="font-size:40px;margin-bottom:8px;">👋</div>
+          <div>No messages yet. Say hello!</div>
+        </div>
+      {% endfor %}
+      <div id="messagesEnd"></div>
+    </div>
+
+    <div class="typing-indicator" id="typingIndicator"></div>
+
+    <div class="chat-input-area">
+      <div class="chat-input-row">
+        <textarea id="messageInput" placeholder="Message #{{ room.name }}..." rows="1"></textarea>
+        <button class="send-btn" id="sendBtn" title="Send (Enter)">➤</button>
+      </div>
+      <div class="text-xs text-muted" style="margin-top:6px;">Press <kbd style="background:var(--bg4);padding:1px 5px;border-radius:3px;">Enter</kbd> to send · <kbd style="background:var(--bg4);padding:1px 5px;border-radius:3px;">Shift+Enter</kbd> for newline</div>
+    </div>
+  </div>
+
+  <!-- RIGHT SIDEBAR -->
+  <div class="room-sidebar">
+
+    <!-- Invite Code -->
+    <div class="panel-section">
+      <div class="panel-title">Invite Code</div>
+      <div class="invite-box">
+        <span class="invite-code" id="inviteCode">{{ room.invite_code }}</span>
+        <button class="btn btn-ghost btn-sm" onclick="copyInvite()" id="copyBtn" title="Copy">⧉</button>
+      </div>
+      <div class="text-xs text-muted mt-2">Share this code to let others join</div>
+    </div>
+
+    <!-- Events -->
+    <div class="panel-section">
+      <div class="flex-center" style="justify-content:space-between;margin-bottom:12px;">
+        <div class="panel-title" style="margin-bottom:0;">Events</div>
+        <a href="{% url 'event_create' room_id=room.id %}" class="btn btn-ghost btn-sm">+ Add</a>
+      </div>
+      <div id="eventsList">
+        {% for event in events %}
+        <a href="{% url 'event_detail' room_id=room.id event_id=event.id %}" class="event-card">
+          <div class="flex-center" style="justify-content:space-between;">
+            <div class="event-title">{{ event.title }}</div>
+            {% if event.is_settled %}<span class="badge badge-green" style="font-size:10px;">✓</span>{% endif %}
+          </div>
+          <div class="event-meta">
+            ${{ event.total_amount|floatformat:2 }}
+            {% if event.event_date %} · {{ event.event_date|date:"M j" }}{% endif %}
+            {% if event.location %} · 📍{{ event.location }}{% endif %}
+          </div>
+        </a>
+        {% empty %}
+        <div class="text-xs text-muted" style="padding:8px 0;">No events yet. Create one!</div>
+        {% endfor %}
+      </div>
+    </div>
+
+    <!-- Members -->
+    <div class="panel-section">
+      <div class="panel-title">Members ({{ members.count }})</div>
+      {% for member in members %}
+      <div class="member-row">
+        <div class="avatar avatar-sm" style="background:{% if member.profile %}{{ member.profile.avatar_color }}{% else %}#6366f1{% endif %};">
+          {% if member.profile %}{{ member.profile.get_avatar_initials }}{% else %}{{ member.username|slice:":2"|upper }}{% endif %}
+        </div>
+        <div>
+          <div class="member-name">{% if member.profile %}{{ member.profile.name }}{% else %}{{ member.username }}{% endif %}</div>
+          <div class="text-xs text-muted">@{{ member.username }}</div>
+        </div>
+      </div>
+      {% endfor %}
+    </div>
+
+  </div>
+</div>
+{% endwith %}
+{% endblock %}
+
+{% block extra_js %}
+<script>
+const ROOM_ID = "{{ room.id }}";
+const CURRENT_USER = "{{ user.username }}";
+const DISPLAY_NAME = "{{ profile.name }}";
+const AVATAR_COLOR = "{{ profile.avatar_color }}";
+const INITIALS = "{{ profile.get_avatar_initials }}";
+
+// ── WebSocket ──
+const wsScheme = window.location.protocol === 'https:' ? 'wss' : 'ws';
+const wsUrl = `${wsScheme}://${window.location.host}/ws/chat/${ROOM_ID}/`;
+let socket = null;
+
+function connectWS() {
+  socket = new WebSocket(wsUrl);
+  socket.onopen = () => console.log('WS connected');
+  socket.onclose = () => { console.log('WS closed, reconnecting…'); setTimeout(connectWS, 2000); };
+  socket.onerror = (e) => console.error('WS error', e);
+  socket.onmessage = (e) => handleMessage(JSON.parse(e.data));
+}
+
+function handleMessage(data) {
+  switch(data.type) {
+    case 'chat_message':
+      appendMessage(data);
+      break;
+    case 'user_join':
+      appendSystem(`${data.display_name} joined the room`);
+      break;
+    case 'user_leave':
+      appendSystem(`${data.display_name} left the room`);
+      break;
+    case 'room_update':
+      if (data.update_type === 'new_event') {
+        appendSystem(`📅 New event: ${data.event_title} (by ${data.created_by})`);
+        // Refresh event list
+        setTimeout(() => location.reload(), 1200);
+      } else if (data.update_type === 'new_expense') {
+        appendSystem(`💸 ${data.paid_by} added $${data.amount} – ${data.expense_description}`);
+      }
+      break;
+  }
+}
+
+function appendMessage(data) {
+  const container = document.getElementById('chatMessages');
+  const isOwn = data.sender === CURRENT_USER;
+  const div = document.createElement('div');
+  div.className = `msg-row${isOwn ? ' own' : ''}`;
+  div.innerHTML = `
+    ${!isOwn ? `<div class="avatar avatar-sm" style="background:${data.avatar_color};margin-top:4px;">${data.initials}</div>` : ''}
+    <div>
+      ${!isOwn ? `<div class="msg-sender">${data.display_name}</div>` : ''}
+      <div class="msg-bubble ${isOwn ? 'own' : 'other'}">${escapeHtml(data.content)}</div>
+      <div class="msg-meta" ${isOwn ? 'style="text-align:right"' : ''}>${data.timestamp}</div>
+    </div>
+  `;
+  container.insertBefore(div, document.getElementById('messagesEnd'));
+  scrollToBottom();
+}
+
+function appendSystem(text) {
+  const container = document.getElementById('chatMessages');
+  const div = document.createElement('div');
+  div.className = 'msg-row';
+  div.style.justifyContent = 'center';
+  div.innerHTML = `<div class="msg-bubble system">${escapeHtml(text)}</div>`;
+  container.insertBefore(div, document.getElementById('messagesEnd'));
+  scrollToBottom();
+}
+
+function sendMessage() {
+  const input = document.getElementById('messageInput');
+  const content = input.value.trim();
+  if (!content || !socket || socket.readyState !== WebSocket.OPEN) return;
+  socket.send(JSON.stringify({ type: 'chat_message', content }));
+  input.value = '';
+  input.style.height = 'auto';
+}
+
+function scrollToBottom() {
+  const container = document.getElementById('chatMessages');
+  container.scrollTop = container.scrollHeight;
+}
+
+function escapeHtml(str) {
+  return str.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/\n/g,'<br>');
+}
+
+function copyInvite() {
+  navigator.clipboard.writeText('{{ room.invite_code }}');
+  const btn = document.getElementById('copyBtn');
+  btn.textContent = '✓';
+  setTimeout(() => btn.textContent = '⧉', 1500);
+}
+
+// ── Event Listeners ──
+document.getElementById('sendBtn').addEventListener('click', sendMessage);
+document.getElementById('messageInput').addEventListener('keydown', (e) => {
+  if (e.key === 'Enter' && !e.shiftKey) {
+    e.preventDefault();
+    sendMessage();
+  }
+});
+
+// Auto-resize textarea
+document.getElementById('messageInput').addEventListener('input', function() {
+  this.style.height = 'auto';
+  this.style.height = Math.min(this.scrollHeight, 120) + 'px';
+});
+
+// Init
+connectWS();
+scrollToBottom();
+</script>
+{% endblock %}

splitchat/core/templates/core/room_form.html

@@ -0,0 +1,25 @@
+{% extends 'core/base.html' %}
+{% block title %}{{ action }} Room – SplitChat{% endblock %}
+{% block content %}
+<div class="page-header"><div><h1 class="page-title">{{ action }} Room</h1></div></div>
+<div class="page-body">
+  <div style="max-width:480px;">
+    <div class="card">
+      <form method="post">
+        {% csrf_token %}
+        {% for field in form %}
+        <div class="form-group">
+          <label>{{ field.label }}</label>
+          {{ field }}
+          {% if field.errors %}<div class="error-list">{{ field.errors.0 }}</div>{% endif %}
+        </div>
+        {% endfor %}
+        <div class="flex gap-2" style="margin-top:8px;">
+          <button type="submit" class="btn btn-primary">{{ action }} Room</button>
+          <a href="{% url 'dashboard' %}" class="btn btn-secondary">Cancel</a>
+        </div>
+      </form>
+    </div>
+  </div>
+</div>
+{% endblock %}

splitchat/core/templates/core/room_join.html

@@ -0,0 +1,23 @@
+{% extends 'core/base.html' %}
+{% block title %}Join Room – SplitChat{% endblock %}
+{% block content %}
+<div class="page-header"><div><h1 class="page-title">Join a Room</h1></div></div>
+<div class="page-body">
+  <div style="max-width:400px;">
+    <div class="card">
+      <p class="text-muted text-sm" style="margin-bottom:20px;">Enter an invite code to join an existing room.</p>
+      <form method="post">
+        {% csrf_token %}
+        <div class="form-group">
+          <label>Invite Code</label>
+          <input type="text" name="invite_code" placeholder="e.g. AB3F9E21" style="font-family:var(--mono);letter-spacing:.1em;text-transform:uppercase;" required>
+        </div>
+        <div class="flex gap-2">
+          <button type="submit" class="btn btn-primary">Join Room</button>
+          <a href="{% url 'dashboard' %}" class="btn btn-secondary">Cancel</a>
+        </div>
+      </form>
+    </div>
+  </div>
+</div>
+{% endblock %}

splitchat/core/tests.py

@@ -0,0 +1,3 @@
+from django.test import TestCase
+
+# Create your tests here.

splitchat/core/urls.py

@@ -0,0 +1,24 @@
+from django.urls import path
+from . import views
+
+urlpatterns = [
+    path('', views.dashboard, name='dashboard'),
+    path('signup/', views.signup_view, name='signup'),
+    path('login/', views.login_view, name='login'),
+    path('logout/', views.logout_view, name='logout'),
+
+    # Rooms
+    path('rooms/create/', views.room_create, name='room_create'),
+    path('rooms/join/', views.room_join, name='room_join'),
+    path('rooms/join/<str:invite_code>/', views.room_join_link, name='room_join_link'),
+    path('rooms/<str:room_id>/', views.room_detail, name='room_detail'),
+
+    # Events
+    path('rooms/<str:room_id>/events/create/', views.event_create, name='event_create'),
+    path('rooms/<str:room_id>/events/<str:event_id>/', views.event_detail, name='event_detail'),
+    path('rooms/<str:room_id>/events/<str:event_id>/settle/', views.event_settle, name='event_settle'),
+    path('rooms/<str:room_id>/events/<str:event_id>/expenses/', views.expense_create, name='expense_create'),
+
+    # API
+    path('api/rooms/<str:room_id>/messages/', views.api_room_messages, name='api_room_messages'),
+]

splitchat/core/views.py

@@ -0,0 +1,348 @@
+import json
+from decimal import Decimal
+from asgiref.sync import async_to_sync
+from channels.layers import get_channel_layer
+from django.shortcuts import render, redirect, get_object_or_404
+from django.contrib.auth import login, logout, authenticate
+from django.contrib.auth.decorators import login_required
+from django.contrib.auth.forms import AuthenticationForm
+from django.contrib.auth.models import User
+from django.contrib import messages
+from django.http import JsonResponse
+from django.views.decorators.http import require_POST, require_GET
+from django.db.models import Sum, Q
+from django.utils import timezone
+
+from .models import ChatRoom, Membership, Message, Event, Expense, ExpenseSplit, UserProfile
+from .forms import SignUpForm, ChatRoomForm, EventForm, ExpenseForm
+
+AVATAR_COLORS = [
+    '#6366f1', '#8b5cf6', '#ec4899', '#f43f5e',
+    '#f97316', '#eab308', '#22c55e', '#14b8a6', '#3b82f6'
+]
+
+
+def get_or_create_profile(user):
+    profile, created = UserProfile.objects.get_or_create(user=user)
+    if created:
+        color_idx = user.id % len(AVATAR_COLORS)
+        profile.avatar_color = AVATAR_COLORS[color_idx]
+        profile.save()
+    return profile
+
+
+# ─── Auth ───────────────────────────────────────────────────────────────────
+
+def signup_view(request):
+    if request.user.is_authenticated:
+        return redirect('dashboard')
+    form = SignUpForm(request.POST or None)
+    if request.method == 'POST' and form.is_valid():
+        user = form.save()
+        profile = get_or_create_profile(user)
+        login(request, user)
+        messages.success(request, f'Welcome, {user.username}!')
+        return redirect('dashboard')
+    return render(request, 'core/auth.html', {'form': form, 'mode': 'signup'})
+
+
+def login_view(request):
+    if request.user.is_authenticated:
+        return redirect('dashboard')
+    form = AuthenticationForm(request, request.POST or None)
+    if request.method == 'POST' and form.is_valid():
+        user = form.get_user()
+        get_or_create_profile(user)
+        login(request, user)
+        return redirect(request.GET.get('next', 'dashboard'))
+    return render(request, 'core/auth.html', {'form': form, 'mode': 'login'})
+
+
+@login_required
+def logout_view(request):
+    logout(request)
+    return redirect('login')
+
+
+# ─── Dashboard ───────────────────────────────────────────────────────────────
+
+@login_required
+def dashboard(request):
+    profile = get_or_create_profile(request.user)
+    rooms = ChatRoom.objects.filter(
+        memberships__user=request.user, memberships__is_active=True
+    ).prefetch_related('memberships')
+
+    upcoming_events = Event.objects.filter(
+        room__memberships__user=request.user,
+        room__memberships__is_active=True,
+        is_settled=False,
+    ).select_related('room').order_by('event_date', '-created_at')[:10]
+
+    # Compute overall balance
+    total_owed = Decimal('0')    # others owe me
+    total_owing = Decimal('0')   # I owe others
+
+    events_with_balance = Event.objects.filter(
+        room__memberships__user=request.user,
+        room__memberships__is_active=True,
+        is_settled=False,
+    )
+    for event in events_with_balance:
+        balances = event.compute_balances()
+        bal = balances.get(request.user.id, Decimal('0'))
+        if bal > 0:
+            total_owed += bal
+        else:
+            total_owing += abs(bal)
+
+    return render(request, 'core/dashboard.html', {
+        'rooms': rooms,
+        'upcoming_events': upcoming_events,
+        'total_owed': total_owed,
+        'total_owing': total_owing,
+        'net_balance': total_owed - total_owing,
+        'profile': profile,
+    })
+
+
+# ─── Rooms ───────────────────────────────────────────────────────────────────
+
+@login_required
+def room_create(request):
+    form = ChatRoomForm(request.POST or None)
+    if request.method == 'POST' and form.is_valid():
+        room = form.save(commit=False)
+        room.created_by = request.user
+        room.save()
+        Membership.objects.create(user=request.user, room=room, is_admin=True)
+        messages.success(request, f'Room "{room.name}" created!')
+        return redirect('room_detail', room_id=str(room.id))
+    return render(request, 'core/room_form.html', {'form': form, 'action': 'Create'})
+
+
+@login_required
+def room_join(request):
+    if request.method == 'POST':
+        code = request.POST.get('invite_code', '').strip().upper()
+        try:
+            room = ChatRoom.objects.get(invite_code=code)
+            membership, created = Membership.objects.get_or_create(
+                user=request.user, room=room,
+                defaults={'is_active': True}
+            )
+            if not created and not membership.is_active:
+                membership.is_active = True
+                membership.save()
+            messages.success(request, f'Joined "{room.name}"!')
+            return redirect('room_detail', room_id=str(room.id))
+        except ChatRoom.DoesNotExist:
+            messages.error(request, 'Invalid invite code.')
+    return render(request, 'core/room_join.html')
+
+
+@login_required
+def room_join_link(request, invite_code):
+    room = get_object_or_404(ChatRoom, invite_code=invite_code)
+    membership, created = Membership.objects.get_or_create(
+        user=request.user, room=room, defaults={'is_active': True}
+    )
+    if not created and not membership.is_active:
+        membership.is_active = True
+        membership.save()
+    return redirect('room_detail', room_id=str(room.id))
+
+
+@login_required
+def room_detail(request, room_id):
+    room = get_object_or_404(ChatRoom, id=room_id)
+    membership = get_object_or_404(Membership, user=request.user, room=room, is_active=True)
+    profile = get_or_create_profile(request.user)
+
+    messages_qs = Message.objects.filter(room=room).select_related('sender', 'sender__profile').order_by('created_at')
+    members = User.objects.filter(memberships__room=room, memberships__is_active=True).select_related('profile')
+    events = room.events.select_related('created_by').all()
+
+    # Enrich members with profiles
+    for m in members:
+        get_or_create_profile(m)
+
+    return render(request, 'core/room_detail.html', {
+        'room': room,
+        'membership': membership,
+        'messages': messages_qs,
+        'members': members,
+        'events': events,
+        'profile': profile,
+        'user': request.user,
+    })
+
+
+# ─── Events ──────────────────────────────────────────────────────────────────
+
+@login_required
+def event_create(request, room_id):
+    room = get_object_or_404(ChatRoom, id=room_id)
+    get_object_or_404(Membership, user=request.user, room=room, is_active=True)
+
+    form = EventForm(request.POST or None)
+    if request.method == 'POST' and form.is_valid():
+        event = form.save(commit=False)
+        event.room = room
+        event.created_by = request.user
+        event.save()
+
+        # Send system message to room
+        msg = Message.objects.create(
+            room=room, sender=request.user,
+            content=f'📅 Created event: **{event.title}**',
+            msg_type='event'
+        )
+        _broadcast_room_update(room_id, 'new_event', {
+            'event_id': str(event.id),
+            'event_title': event.title,
+            'created_by': request.user.username,
+        })
+        messages.success(request, f'Event "{event.title}" created!')
+        return redirect('event_detail', room_id=str(room.id), event_id=str(event.id))
+
+    return render(request, 'core/event_form.html', {'form': form, 'room': room})
+
+
+@login_required
+def event_detail(request, room_id, event_id):
+    room = get_object_or_404(ChatRoom, id=room_id)
+    get_object_or_404(Membership, user=request.user, room=room, is_active=True)
+    event = get_object_or_404(Event, id=event_id, room=room)
+
+    expenses = event.expenses.select_related('paid_by').prefetch_related('splits__user')
+    members = User.objects.filter(memberships__room=room, memberships__is_active=True)
+    for m in members:
+        get_or_create_profile(m)
+
+    balances = event.compute_balances()
+    settlements = event.compute_settlements()
+
+    expense_form = ExpenseForm(room=room)
+
+    # Enrich balances with user objects
+    balance_display = []
+    for uid, amount in balances.items():
+        try:
+            u = User.objects.select_related('profile').get(id=uid)
+            get_or_create_profile(u)
+            balance_display.append({'user': u, 'amount': amount})
+        except User.DoesNotExist:
+            pass
+
+    return render(request, 'core/event_detail.html', {
+        'room': room,
+        'event': event,
+        'expenses': expenses,
+        'members': members,
+        'balance_display': sorted(balance_display, key=lambda x: x['amount'], reverse=True),
+        'settlements': settlements,
+        'expense_form': expense_form,
+        'profile': get_or_create_profile(request.user),
+    })
+
+
+@login_required
+@require_POST
+def expense_create(request, room_id, event_id):
+    room = get_object_or_404(ChatRoom, id=room_id)
+    get_object_or_404(Membership, user=request.user, room=room, is_active=True)
+    event = get_object_or_404(Event, id=event_id, room=room)
+
+    form = ExpenseForm(request.POST, room=room)
+    if form.is_valid():
+        amount = form.cleaned_data['amount']
+        paid_by = form.cleaned_data['paid_by']
+        participants = form.cleaned_data['participants']
+        split_type = form.cleaned_data['split_type']
+        description = form.cleaned_data['description']
+
+        expense = Expense.objects.create(
+            event=event,
+            description=description,
+            amount=amount,
+            paid_by=paid_by,
+            split_type=split_type,
+        )
+
+        if split_type == Expense.SPLIT_EQUAL:
+            per_person = (amount / len(participants)).quantize(Decimal('0.01'))
+            for participant in participants:
+                ExpenseSplit.objects.create(expense=expense, user=participant, amount=per_person)
+        else:
+            # Custom: equal for now, can be extended
+            per_person = (amount / len(participants)).quantize(Decimal('0.01'))
+            for participant in participants:
+                custom_key = f'custom_{participant.id}'
+                custom_amount = request.POST.get(custom_key)
+                if custom_amount:
+                    try:
+                        amt = Decimal(custom_amount)
+                    except Exception:
+                        amt = per_person
+                else:
+                    amt = per_person
+                ExpenseSplit.objects.create(expense=expense, user=participant, amount=amt)
+
+        _broadcast_room_update(room_id, 'new_expense', {
+            'event_id': str(event.id),
+            'event_title': event.title,
+            'expense_description': description,
+            'amount': str(amount),
+            'paid_by': paid_by.username,
+        })
+
+        messages.success(request, f'Expense "${amount} – {description}" added!')
+    else:
+        messages.error(request, 'Invalid expense data.')
+
+    return redirect('event_detail', room_id=str(room.id), event_id=str(event.id))
+
+
+@login_required
+@require_POST
+def event_settle(request, room_id, event_id):
+    room = get_object_or_404(ChatRoom, id=room_id)
+    get_object_or_404(Membership, user=request.user, room=room, is_active=True)
+    event = get_object_or_404(Event, id=event_id, room=room)
+    event.is_settled = True
+    event.save()
+    messages.success(request, f'Event "{event.title}" marked as settled!')
+    return redirect('event_detail', room_id=str(room.id), event_id=str(event.id))
+
+
+# ─── API endpoints ───────────────────────────────────────────────────────────
+
+@login_required
+def api_room_messages(request, room_id):
+    room = get_object_or_404(ChatRoom, id=room_id)
+    get_object_or_404(Membership, user=request.user, room=room, is_active=True)
+    msgs = Message.objects.filter(room=room).select_related('sender', 'sender__profile').order_by('-created_at')[:50]
+    data = [{
+        'id': str(m.id),
+        'content': m.content,
+        'sender': m.sender.username if m.sender else 'deleted',
+        'display_name': (m.sender.profile.name if hasattr(m.sender, 'profile') else m.sender.username) if m.sender else 'deleted',
+        'timestamp': m.created_at.strftime('%H:%M'),
+        'type': m.msg_type,
+    } for m in reversed(list(msgs))]
+    return JsonResponse({'messages': data})
+
+
+# ─── Helpers ─────────────────────────────────────────────────────────────────
+
+def _broadcast_room_update(room_id, update_type, payload):
+    channel_layer = get_channel_layer()
+    if channel_layer:
+        try:
+            async_to_sync(channel_layer.group_send)(
+                f'chat_{room_id}',
+                {'type': 'room_update', 'update_type': update_type, **payload}
+            )
+        except Exception:
+            pass

splitchat/manage.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+"""Django's command-line utility for administrative tasks."""
+import os
+import sys
+
+
+def main():
+    """Run administrative tasks."""
+    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'config.settings')
+    try:
+        from django.core.management import execute_from_command_line
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) from exc
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == '__main__':
+    main()

splitchat/render.yaml

@@ -0,0 +1,38 @@
+services:
+  # Web service (Django + Daphne ASGI)
+  - type: web
+    name: splitchat
+    runtime: python
+    buildCommand: "./build.sh"
+    startCommand: "daphne -b 0.0.0.0 -p $PORT config.asgi:application"
+    envVars:
+      - key: SECRET_KEY
+        generateValue: true
+      - key: DEBUG
+        value: "False"
+      - key: ALLOWED_HOSTS
+        value: ".onrender.com"
+      - key: DATABASE_URL
+        fromDatabase:
+          name: splitchat-db
+          property: connectionString
+      - key: REDIS_URL
+        fromService:
+          name: splitchat-redis
+          type: redis
+          property: connectionString
+      - key: PYTHON_VERSION
+        value: "3.11.0"
+
+  # Redis for Django Channels
+  - type: redis
+    name: splitchat-redis
+    plan: free
+    maxmemoryPolicy: noeviction
+
+databases:
+  # PostgreSQL
+  - name: splitchat-db
+    plan: free
+    databaseName: splitchat
+    user: splitchat

splitchat/requirements.txt

@@ -0,0 +1,9 @@
+Django==4.2.16
+channels==4.1.0
+channels-redis==4.2.0
+daphne==4.1.2
+django-environ==0.11.2
+dj-database-url==2.2.0
+psycopg[binary]==3.3.4
+whitenoise==6.7.0
+gunicorn==22.0.0